Slaves
The Oracle's warning had been clear: corrupt handlers were overseeing the exam, and Emery knew without a doubt that the Nephilim were involved. Rather than passively awaiting the ambush, Emery chose to act preemptively. His target was none other than the magus handler assigned to Hall 33, the one likely in league with his enemies.
The day before the exam began, Emery captured the magus handler in secret. For several hours, he painstakingly cast his [Soul Enslavement] spell, breaking the magus's will and unraveling the truth. The handler had indeed been bought by the Nephilim, accepting their bribe to ensure the sabotage of Hall 33.
With his mind fully enslaved, the magus handler would carry out his duties as usual, arousing no suspicion among his peers. He would follow the prearranged plan, stay close to the other handlers, and ensure that the ambush against Hall 33 would proceed as the Nephilim intended.
Everything unfolded according to Emery's design.